Switch assembly

Abstract: A switch assembly having a rocker type actuator user rotatable for sequentially actuating plural switches. The rocker contacts, off center a lever beam supported at its end by plungers disposed to actuate the individual membrane switches or optical activators. User applications of an initial force to the rocker causes the lever beam to pivot about the remote plunger for actuation of the switch closest to the rocker contact point. After actuation of the closest switch, user application of a greater force continues rotation of the rocker to cause the lever beam to pivot about the closest plunger for causing actuation of the remote switch. Overtravel is shared by beam deflection of the lever and columnar compression of cylindrical tower portions of the resilient membranes.

Description: BACKGROUND OF THE INVENTION The present invention relates to switches and particularly switches of the type having a pivotally mounted actuator or rocker member rotatable by the user in a clockwise and anti-clockwise direction for actuation of selected switching mechanisms to control a desired circuit function. Switches actuated by a rocker member have found particularly widespread usage in automotive applications for user remote control of various vehicle accessories such as window lift motors, door lock solenoids and mirror adjustment motors. Typically, such automotive switch applications operate at a low direct current voltage such as twelve volts; and have been required to switch substantial currents on the order of ten to twenty amperes direct current at twelve volts for providing the control of the accessory motor. In such automotive vehicle accessory motor remote control applications, it has been commonplace to employ snap acting switches for switching the motor load current. Snap acting switch mechanisms have inherently provided internal spring biasing which must be overcome to effect switch actuation and have thus provided a tactilely discernable feedback to the user of the switch actuation. However, in switching applications where low current loads are to be remotely controlled as for example in circuit systems where only fractional or milliampere signal currents are to be switched, it has been found unnecessary to utilize a snap acting switch mechanism; thus, the complexity and cost of the snap acting mechanism may be eliminated. Where such low current switches are employed, it has been found that there is no inherent tactilely discernable force feedback to the user indicating the state of actuation of the switching mechanism. Thus, in automotive applications where the user is accustomed to rocker type switch actuation with tactilely discernable indication of the state of switch actuation, it has been desired to emulate the switch actuation characteristics of the snap acting switching mechanism yet to provide such actuation in a low cost switching mechanism employing direct movement of the contacts without the inherent spring forces associated with a snap acting mechanism. In certain switch applications, it has been desired to provide sequential actuation of plural switches by user movement of the actuation rocker member in one direction. This type of sequential plural switch actuation has been employed in automotive applications where it was desired to provide an "express" or automatic down or lowering function for powered window motors to permit user relaxation of the switch rocker yet provide continuous downward movement of the window to its lower opening limit. Upon user movement of the switch rocker actuator member to a rotated position in such systems, the window motor is energized to lower the window; and, so long as the user maintains the rocker in that position the motor will continue running. However, if the user rotates the rocker further beyond the motor actuation position, to a second tactilely discernable position, an electronic control circuit is energized to maintain the motor running despite subsequent user relaxation of the actuation force from the rocker and the returning of the rocker to its neutral or "off" position or allowing the rocker to self return to the neutral position. Where snap acting switches are employed for switching the powered window motor current, the inherent spring forces in the snap acting switch mechanism are readily tactilely discernable by the switch user upon movement of the rocker actuator member. However, where relays are employed which permits the use of low current switches in automotive accessory remote control applications such, as for example, powered window motor remote control, it has thus been desired to provide a way or means of providing a tactilely discernable feedback of the switch actuation without employing costly snap acting switching mechanisms. From US-A-4967043 there is known a rocker actuated switch assembly comprising: (a) housing means; (b) a first switch mounted on said housing means including an actuator member resiliently biased to a first switch position wherein said first switch is in an first position and moveable between said switch first position and a switch second position wherein said first switch is in a second condition; (c) a second switch mounted on said housing means spaced from said first switch, said second switch including an actuator member resiliently biased to a first position wherein said second switch is a first condition and moveable to a second position wherein said second switch is in a second condition; (d) first plunger means movably disposed on said housing means and operable upon movement to contact said first switch actuator and effect movement thereof between said first and said second positions; (e) second plunger movably disposed on said housing means and operable upon movement to contact said second switch actuator member and effect movement thereof between said first and said second condition; (f) a rocker member pivotally mounted for pivotal movement in opposite directions on said housing means and disposed with said first and second switches on a common side of said pivotal mount; (g) a third switch mounted on said base means on the side of said pivotal mount of said first and second switch; wherein, upon user application of an initial force movement of said rocker in one of said directions is effected and, (h) wherein user movement of said rocker in the other of said opposite directions is operative to the effect actuation of said third switch. From US-A-4967043 there is also known a method of providing tactilely discernable actuators of a pair of switches each having a resiliently biased actuator by user movement of a single rocker in one direction, disposing individual plungers moveable for operatively contacting each of said switches. SUMMARY OF THE INVENTION The present invention provides a switch assembly actuated by user rotation of a rocker or actuating member in opposite directions about a pivot. In at least one direction of movement the rocker member is effective to sequentially actuate a plurality of switches. A first and second switch are mounted on a common side of the rocker pivot and each is disposed for actuation by a plunger member slidably mounted on the housing. A lever member is disposed with opposite ends supported by the plungers. The switches are biased to the open condition; and, where membrane type switches are employed, by the resiliency of the membrane. Upon application by the user of an initial force and movement of the rocker in one direction, the rocker contacts the lever intermediate the midpoint and one end and overcomes the bias of one of the switches to effect actuation thereof. Upon subsequent application of a force tactilely discernible greater than the initial force, further movement of the rocker member in the same direction occurs; and, the lever is pivoted about the plunger of the actuated switch to effect actuation of the other switch. Rotation of the rocker member in the opposite direction through the neutral position provides actuation of a third switch. The switch mechanism of the present invention has found particular application in switches of the type having contacts mounted on resilient elastomeric domes or membranes for actuation by the individual sliding plungers. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a portion of a cross-sectional view of the assembly of the present invention showing the rocker in the neutral or unactuated position; FIG. 2 is a view similar to FIG. 1 showing the rocker rotated anti-clockwise an amount actuating one of the switches; FIG. 3 is a view similar to FIG. 2 showing the rocker rotated an additional amount from the position of FIG. 2 sufficient to actuate the second switch; FIG. 4 is a view similar to FIG. 3 showing the actuator rocker rotated further in an anti-clockwise direction from the position of FIG. 3 to an over traveled position; FIG. 5 is a view similar to FIG. 1 showing the rocker actuator rotated in a clockwise direction from the position of FIG. 4 to a position again as shown if FIG. 3; FIG. 6 is a view similar to FIG. 1 showing the actuator rotated in a clockwise direction from the position shown in FIG. 5 to a position coinciding with that of FIG. 2; FIG. 7 is a portion of a section's view taken along section-indicating lines 7-7 of FIG. 1; FIG. 8 is a view similar to FIG. 1 illustrating another embodiment of the invention; and, FIG. 9 is a view similar to FIG. 1 illustrating another embodiment of the invention. DETAILED DESCRIPTION Referring to FIG. 1, the switch assembly of the present invention is indicated generally at 10 and has a housing means comprising a cover member 14 and base 12 preferably formed of suitable insulating material such as plastic. The base has a plurality of elastomeric membranes or domes provided thereon in spaced relationship as indicated by referenced numerals 16, 18, 20 which are preferably formed of elastomeric material with each membrane having a conductive electrical contact or pad on the underside thereof as denoted by referenced numerals 22, 24, 26. The switch membranes 16, 18 are located on a common side of a pivot surface 28. In the presently preferred practice, the pivot surface 28 is provided on an upstanding lug or stanchion 30 formed integrally with cover 14 and upon which is pivotally mounted a rocker member 32 which has a paddle portion 34 extending outwardly of the cover 14. It will be understood however that other arrangements of the pivot surface may be employed. Membranes 16, 18 have cylindrical tower portions, denoted by reference numerals 34, 36 respectively, provided in the center thereof adjacent the contacts 22, 24 which tower portions are each preferably formed integrally with the respective membrane 16, 18. Each of the cylindrical tower portions 34, 36 is contacted respectively by a head portion, denoted respectively by referenced numeral 38, 40, of a plunger, denoted respectively 42, 44, slidably mounted in the cover 14 and with portions thereof extending upwardly and outwardly of the cover. A third plunger 46 is slidably disposed in a similarly manner on the opposite side of the pivot 28 from plungers 42, 44 and has its head portion 47 positioned for contacting membrane 26 at its center. Referring to FIGS. 1 and 7, a lever means in the form of beam member 48 is disposed between the plungers 42, 44 and supported at its opposite ends by the upper ends of the plungers 42, 44. The upper surface of the beam 48 is contacted by a pivot surface 50 defined on the left hand side of rocker 32 which contacts the beam 48 at a point intermediate to mid-length and the right hand end thereof. It will be understood that by changing the point of contacts of rocker surface 50 along beam 48 that different actuating forces can be applied to the domes 16,18. With reference to FIG. 7, the beam 48 preferably has a pair of oppositely extending trunnions 52, 54 provided centrally thereon which engage slots 56, 58 formed in the sides of the cover 14; and, the trunnions 52, 54 are guided for vertical sliding movement in the slots 56, 58. It will be understood that trunnions 52, 54 are also free to pivot in the slots 56, 58. Although trunnions have been shown and described as a means for pivoting the lever it will be understood that other techniques may be employed for pivoting the lever. Referring to FIG. 1, the rocker 32 is shown in the neutral or unactuated position with the switch membranes or domes 16, 18 fully extended in an upward direction with the contacts 22, 24 raised or spaced from the base 12 to provide an open circuit condition for their respective stationary contacts located thereunder (not shown) on the base 12. It will be understood that the base 12 contains a printed circuit (not shown) on the upper surface thereof with a pair of spaced contacts below each of the movable contacts 22, 24 for providing an electrical switching function wherein contacts 22, 24 act as shorting bars as is well known in the art; and, details thereof have been omitted for the sake of brevity. In the unactuated or neutral position of the rocker shown in FIG. 1, the plungers 42, 44 are in their limit of upward movement with beam 48 having its trunnions 52, 54 raised in the slots as illustrated for the slot 58. Referring to FIG. 2, rocker member 32 has been rotated in the anti-clockwise direction by user application of an initial force on the right side of paddle 33 which initial force is sufficient to cause beam 48 to pivot about the end of plunger 42 pushing plunger 44 and head 40 downwardly against the cylindrical portion 36 of membrane 18 and causing the membrane 18 to collapse and permit contact 24 to act as a shorting bar and close a circuit between a pair of contacts (not shown) on the base 12. Referring to FIG. 3, the rocker member 32 has been rotated further in the anti-clockwise direction from the position shown in FIG. 2 by user application of a force to the right hand side of paddle 33 which force is greater than the initial force so as to pivot beam 48 about the end of plunger 44. It will be understood that the surface 50 on rocker 32 acts about the fulcrum of member 48 on the end of plunger 44 at a mechanical disadvantage with respect to the reaction forces of plunger 42 and thus the greater force is required to effect pivoting of beam 48 about the end of plunger 44 than is required to pivot the beam 48 about the end of plunger 42 for membranes 16, 18 having the same configuration and resilient stiffness. In the present practice of the invention the force required to effect movement of beam 48 about the end of plunger 44 is on the order of two to three times greater than the initial force required to pivot beam 48 about plunger 42 and collapse membrane 18 for closing contact 24 against the base 12. In FIG. 3, rocker 32 is shown as having beam 48 pivoted about the end of plunger 44 to depress plunger 42 with membrane 16 collapsed for closing contact 22 against a pair of spaced contacts (not shown) on base 12 for closing a circuit. It will be observed in FIGS. 2 and 3 that the reaction on plunger 44 of the additional force being applied to paddle 33 and transmitted via rocker 32 and surface 50 to beam 48 causes beam 48 to apply a force to the cylindrical tower portion 36 of the membrane 18 sufficient to cause columnar deflection thereof; and, subsequent application of the greater force to paddle 34 and to beam 48 via surface 50 for effecting collapse of membrane 16 causes a similar columnar deflection of tower portion 34 of the membrane 18. This columnar deflection in tower portions 36, 34 is illustrated in FIGS. 2 and 3 by a diametral bulging of the cylindrical tower portions. Referring to FIG. 4, the rocker 32 is shown in an overtraveled position wherein the user has applied a force greater than the initial force to paddle 33 and maintained such a greater force thereon after beam 48 has acted on plunger 42 and caused the contact 22 to collapse membrane 18. The greater force applied to beam 48 has caused beam 48 to deflect and further columnar deformation and bulging of cylindrical membrane cylindrical tower 34 and similarly by columnar compression and balding of membrane cylindrical tower 36 by virtue of the increased load transmitted through plunger 44. It will be understood from FIG. 4 that overtravel of rocker 32 is partially absorbed by deflection of beam 48 and partially absorbed by the columnar deflection of membrane cylindrical towers 38, 36. It will be understood that rocker overtravel may also be accommodated by providing telescoping spring plungers and/or providing a beam spring for the lever 48. Referring to FIG. 5, the rocker 32 has been moved by a slight amount in the clockwise direction from the position shown in FIG. 4 by user relaxation of the greater force applied to paddle 33. In the position shown in FIG. 5, the membrane cylindrical tower 34 has been relaxed from its bulged columnar deflection as has been beam 48, with the result that membrane 16 has raised contact 22 a slight amount so as to break the circuit from the contacts (not shown) on the base 12. The condition of the switch assembly shown in FIG. 5 would thus be considered as a circuit break or reset condition for contact 22. It will be understood that the force maintained on paddle 33 causes rocker 32 via surface 50 to maintain beam 48 pivoted about the upper end of plunger 42 and maintains plunger 44 in the downward position closing contact 24 against the base 12 and maintaining some columnar deflection and bulging in membrane cylindrical tower 36. Referring to FIG. 6, the user applied force to paddle 33 has been relaxed an additional amount from that of FIG. 5 permitting rocker 32 via surface 50 to allow membrane 16 to raise to the fully extended upward position shown in FIG. 6 raising contact 22 to its upward limit of open circuit condition. The beam 48 is also pivoted about the end of plunger 42 to permit membrane tower 36 to relax from its columnar deflected and bulged condition and to permit contact 24 to raise a slight amount from base 12 thereby breaking the circuit made by contact 24. The condition of the switch in FIG. 6 is thus that of open circuit for contact 24 or reset position thereof. Referring to FIG. 8, another embodiment of the invention is indicated generally at 100 as having a base 112 and cover 114 with three switching membranes 116,118,120 disposed in spaced relationship. Each of the membranes has a projection extending downwardly from the undersurface of the central region thereof as denoted by reference numerals 122,124,126 in FIG. 8. Each of the membranes 116,118,120 has disposed thereunder a light emitting source, for example, a light emitting diode (LED) denoted respectively by reference numerals 121,123,125 for emitting a beam of light which is detected by a suitable photo-detector disposed spaced adjacent thereto as denoted respectively by reference numerals 127,129,131. The cover 114 has a stanchion 130 provided thereon which defines a pivot surface 128 upon which is pivotally mounted a rocker 132 which has a paddle portion 133 extending externally of the cover for user contact therewith. Membranes 116,118 each have a cylindrical tower portion 134,136 respectively extending upwardly therefrom and which are resiliently deflectable by columnar loading thereon. The cover 114 has slidably mounted therein and positioned in alignment with the central region of each of the membranes 116,118,120 a plunger as denoted respectively by reference numerals 142,144,146. Each of the plungers has an enlarged diameter head portion provided on the lower end thereof as denoted respectively by reference numerals 138,140,147. A lever or beam 148 is disposed between and supported at its ends by the upper ends of plungers 142,144 and is contacted on its upper surface at a desired off center position by the contact surface 150 of rocker member 132. The lever 148 is pivoted at its mid-length by any suitable expedient, as for example, oppositely disposed trunnions formed at the mid-length of the beam, one of which is shown and is denoted by reference numeral 152 in FIG. 8. The trunnions are free to slide vertically in a suitable slot 158 provided in the cover. It will be understood with reference to FIG. 8 that the contact surface 150 of the rocker 132 contacts the beam 148 intermediate the trunnion 152 and the plunger 144. It will be understood that the embodiment of FIG. 8 insofar as movement of the rocker and beam 148 against plungers 142,144 and the resilient deflection of the membranes 116, 118 is similar to that of the embodiment of FIG. 1. However, in the embodiment of FIG. 8, when the force on the plunger heads 138,140 is sufficient to cause collapse of membrane 118 and subsequently membrane 116, the projections 124,122 are caused to move downwardly between the light emitting sources and detectors respectively 123,129 and 121,127 for blocking light transmission therebetween and effecting a switching action. Similarly, user movement of rocker 132 in a clockwise direction sufficient to cause depression of plunger 146 causes plunger head 147 to move membrane 120 downwardly and projection 126 blocks light transmission between source 125 and detector 131. The sequential switch actuation and tactilely discernible force feedback of the embodiment of FIG. 8 is otherwise similar to that of the embodiment of FIG. 1. The embodiment of FIG. 8 thus provides optical coupling or switching with the sequential actuation and tactilely discernable force feedback of the rocker and resiliently mounted lever of the present invention. Referring to FIG. 9, another embodiment of the invention is denoted generally at 200 and includes a body or housing 212 with a cover 214 having pivotally mounted thereon at a pivot surface 228 formed on a stanchion portion 230 of the cover for pivotal movement in opposite directions by user contact with a paddle portion 233 which extends outwardly of the cover from the main portion of the rocker 232. The rocker has a contact surface portion 250 which contacts a lever 248 having pivot trunnions, one of which is shown at 252, engaging slot 258 for vertical movement therein during pivotal movement thereof. The lever 248 is supported at its ends by plungers 242,244 which are each slidably mounted in the cover 214 and which have the lower end thereof configured in a taper for contacting a precise location on a spring blade member of a switch. Referring to FIG. 9, a resilient switch blade member 260 has one end thereof mounted on a stanchion 262 provided on the base 212 and extends generally in cantilever with the free end of the spring blade member 260 formed downwardly generally at right angles thereto. The blade member 260 is contacted by the tapered end of plunger 242 for movement thereby; and, the member 260 is also biased upwardly by one end of a spring member 266 which has the opposite reaction end thereof anchored to the base on a suitable stanchion 268. In the presently preferred practice, the spring 266 provides an over center snap action to blade member 260. A light emitting source 270 is disposed on the base and emits a beam of light which is detected by a photo-detector 272 mounted on the base and disposed adjacent thereto. The source 270 and detector 272 are located such that downward movement of the spring member 260 causes the end 264 thereof to interrupt the light beam from source 270 and effect an optical switching action. Similarly a spring blade member 274 has one end thereof mounted on stanchion 276 with the free end of the member 274 formed downwardly at 278 and the member 274 biased upwardly by a spring member 278 having the opposite reaction end thereof anchored to a stanchion 280. The spring member 274 is disposed to be moved downwardly by the tapered end of plunger 244 in a snap action; and, the free end 278 is operative to effect interruption of a light beam from a light source 282 spaced opposite from a photo-detector 284 to thereby provide a switching action. A third spring blade member 286 has one end thereof mounted on a stanchion 288 provided on the base 212; and, the spring member 286 is biased in an upward direction by a bias spring 290 which has the opposite reaction end thereof mounted on stanchion 288 with the free end of member 286 formed downwardly as denoted by reference numeral 292 for performing a switching action. The end 292 of the member 286 is disposed such that upon downward movement of the end 292 a light beam emitting from a light emitter 294 which is interrupted from being received by a photo-detector 296. The member 286 is disposed to be moved in a downward direction by the tapered end of plunger 246 which is slidably mounted on the opposite side of pivot 228 from the plungers 242,244. It will be understood that the operation of the rocker 232 in effecting pivotal movement of the lever 248 and depression of plungers 242,244 against the resiliently biased switch members 260,264 provides a sequentially increasing force and feedback thereof to the user similar to that of the embodiments of FIGS. 1 and 8. The present invention thus provides optical switching with a tactilely discernable indication of rocker actuated switches by the user movement of the rocker actuator in one direction. The present invention thus provides rocker actuation in one direction for sequentially actuating a plurality of low-current low-force bias switches and provides tactilely discernible force feedbacks to the user of the state of actuation of the individual switches. Although the invention has hereinabove been described with respect to the illustrated embodiments, it will be understood that the invention is capable of modification and variation and is limited only by the following claims.

Claims: A rocker actuated switch assembly comprising: (a) housing means (12,14); (b) a first switch mounted on said housing means including an actuator member (16) resiliently biased to a switch unactuated position wherein said first switch is in an open position and moveable between said switch unactuated position and a switch actuated position wherein said first switch is in a closed condition; (c) a second switch mounted on said housing means spaced from said first switch, said second switch including an actuator member (18) resiliently biased to an unactuated position wherein said second switch is an open condition and moveable to an actuated position wherein said second switch is in a closed condition; (d) first plunger means (42) movably disposed on said housing means and operable upon movement to contact said first switch actuator and effect movement thereof between said unactuated and said actuated positions; (e) second plunger (44) movably disposed on said housing means and operable upon movement to contact said second switch actuator member and effect movement thereof between said unactuated and said actuated condition; (f) a rocker member (32) pivotally mounted for pivotal movement in opposite directions on said housing means and disposed with said first and second switches on a common side of said pivotal mount (28); (g) lever means 48 supported at one end on said first plunger means (42) and on the opposite end of said second plunger means (44) at the other end; (h) a third switch mounted on said base means (12) on the side of said pivotal mount opposite said first and second switch; wherein, upon user application of an initial force movement of said rocker (32) in one of said directions is effected and, said rocker (32) contacts said lever means (48) adjacent one of the plunger means (42,44) and pivots said lever means (48) about the other of said plunger means (42) and overcomes said resilient bias to move the adjacent switch actuator member (18) to the actuated position, whereupon continued user rotation of said rocker (32) in said one direction with a tactilely discernable force greater than said initial force pivots said lever means (48) about said one (44) of said switch actuator members and overcomes the resilient bias of said other of said switch actuator members (16) and moves said other of said switch actuator members to the actuated position; and, (i) wherein user movement of said rocker (32) in the other of said opposite directions is operative to the effect actuation of said third switch. The assembly defined in Claim 1, wherein said third switch means includes a third plunger means (46) movably mounted on said housing means (12,14) and an actuator member (20) moveable between a switch unactuated and an actuated position with said third plunger means (46) disposed intermediate said rocker (32) and said third switch actuator member (2). The assembly defined in Claim 1, wherein said switches include a source emitting a beam of light and a photo-detector positioned to detect the beam; and, said actuator member (16,18,20) is operative to interrupt the beam in the actuated position. A method of using the assembly according to claims 1-3 and thereby providing tactilely discernable actuators of a pair of switches each having a resiliently biased actuator (16,18) by user movement of a single rocker (32) in one direction comprising: (a) disposing individual plungers (42,44) moveable for operatively contacting each of said switches; (b) supporting the opposite ends of a lever (48) respectively on said plungers (42,44); (c) moving the rocker (32) in said one direction and contacting the lever (48) intermediate the midpoint thereof and one of said plungers (42,44) and exerting an initial force on said lever (48) and moving said lever (48) about the other of said plungers (42) and overcoming the bias of the switch actuator (18) adjacent said one plunger (44) and moving said one plunger (44) and effecting actuation of one of said switches; (d) continuing movement of said rocker (32) in said one direction and applying a force tactilely discernable to be greater than said initial force and pivoting the lever (48) about the adjacent switch actuator (44) and moving the plunger (42) and overcoming the resilient bias of the other of said switch actuators (16) effecting actuation of the other switch of the pair. The method defined in Claim 4, further comprising absorbing further movement or overtravel of said rocker (32) by resiliently deflecting said lever. The method defined in Claim 4, wherein said moving of said plungers (42,44) includes slidably moving said plungers. The method defined in Claim 4, wherein said overcoming said bias includes resiliently deflecting a membrane (16,18,20). The method defined in Claim 4, wherein said overcoming said bias includes resiliently deflecting a snap acting mechanism.

Inventors: MALONE PETER GRIMM, MALONE, PETER GRIMM
Applicants: EATON CORP, EATON CORPORATION
Application year: 1994
Main classification: H01H23
IPC codes: H01H23